U.S. Pat. No. 4,488,848 to Kress et al. and assigned to the assignee herein, is directed to a tractor-trailer apparatus having a vertically displaceable hydraulic tong mechanism incorporated in the trailer section for clamping and lifting a straddled load. While this apparatus functions well in certain environments, it is often limited because the bottom of the tractor and a stabilizing link beneath the front of the trailer portion are relatively close to the ground, and because the tractor wheels are narrowly spaced. As a result, to use this apparatus with loads of any substantial height relative to the apparatus, the rear portion of the tractor-trailer must be backed over the load. However, at times it is desirable to be able to drive over a stacked load in either direction; thus such a tractor-trailer apparatus is unsuitable for certain tasks.
Moreover, since the bottom of the lifting vehicle cannot clear loads above a certain height, stacked loads positioned for storage must be arranged to allow these load handling vehicles unencumbered access from either direction. Such a requirement limits flexibility as to the location and pattern of storing loads. However, for a vehicle to provide a substantial amount of flexibility while being designed to vertically clear loads of a relatively large height, the vehicle must be within an envelope having a relatively low and narrow profile and be highly maneuverable. In other words, such a vehicle must be able to minimize its overall height when traveling through narrow and low doorways and other overhead obstructions.